Re: [PATCH] drm/sun4i: Fix crash during suspend after component bind failure
On Wed, 15 Jun 2022 00:42:53 -0500, Samuel Holland wrote: > If the component driver fails to bind, or is unbound, the driver data > for the top-level platform device points to a freed drm_device. If the > system is then suspended, the driver passes this dangling pointer to > drm_mode_config_helper_suspend(), which crashes. > > Fix this by only setting the driver data while the platform driver holds > a reference to the drm_device. > > [...] Applied to drm/drm-misc (drm-misc-fixes). Thanks! Maxime
Re: [PATCH] drm/sun4i: Fix crash during suspend after component bind failure
Hi,
On Wed, Jun 15, 2022 at 12:42:53AM -0500, Samuel Holland wrote:
> If the component driver fails to bind, or is unbound, the driver data
> for the top-level platform device points to a freed drm_device. If the
> system is then suspended, the driver passes this dangling pointer to
> drm_mode_config_helper_suspend(), which crashes.
>
> Fix this by only setting the driver data while the platform driver holds
> a reference to the drm_device.
>
> Fixes: 624b4b48d9d8 ("drm: sun4i: Add support for suspending the display
> driver")
> Signed-off-by: Samuel Holland
Yeah, it's far from the only issue regarding structure lifetimes in the
driver.
We should convert as much as possible to the DRM-managed functions to
fix those.
Maxime
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Re: [PATCH] drm/sun4i: Fix crash during suspend after component bind failure
Dne sreda, 15. junij 2022 ob 07:42:53 CEST je Samuel Holland napisal(a):
> If the component driver fails to bind, or is unbound, the driver data
> for the top-level platform device points to a freed drm_device. If the
> system is then suspended, the driver passes this dangling pointer to
> drm_mode_config_helper_suspend(), which crashes.
>
> Fix this by only setting the driver data while the platform driver holds
> a reference to the drm_device.
>
> Fixes: 624b4b48d9d8 ("drm: sun4i: Add support for suspending the display
driver")
> Signed-off-by: Samuel Holland
Reviewed-by: Jernej Skrabec
Best regards,
Jernej
[PATCH] drm/sun4i: Fix crash during suspend after component bind failure
If the component driver fails to bind, or is unbound, the driver data
for the top-level platform device points to a freed drm_device. If the
system is then suspended, the driver passes this dangling pointer to
drm_mode_config_helper_suspend(), which crashes.
Fix this by only setting the driver data while the platform driver holds
a reference to the drm_device.
Fixes: 624b4b48d9d8 ("drm: sun4i: Add support for suspending the display
driver")
Signed-off-by: Samuel Holland
---
drivers/gpu/drm/sun4i/sun4i_drv.c | 4 +++-
1 file changed, 3 insertions(+), 1 deletion(-)
diff --git a/drivers/gpu/drm/sun4i/sun4i_drv.c
b/drivers/gpu/drm/sun4i/sun4i_drv.c
index 275f7e4a03ae..8841dba989ee 100644
--- a/drivers/gpu/drm/sun4i/sun4i_drv.c
+++ b/drivers/gpu/drm/sun4i/sun4i_drv.c
@@ -73,7 +73,6 @@ static int sun4i_drv_bind(struct device *dev)
goto free_drm;
}
- dev_set_drvdata(dev, drm);
drm->dev_private = drv;
INIT_LIST_HEAD(&drv->frontend_list);
INIT_LIST_HEAD(&drv->engine_list);
@@ -114,6 +113,8 @@ static int sun4i_drv_bind(struct device *dev)
drm_fbdev_generic_setup(drm, 32);
+ dev_set_drvdata(dev, drm);
+
return 0;
finish_poll:
@@ -130,6 +131,7 @@ static void sun4i_drv_unbind(struct device *dev)
{
struct drm_device *drm = dev_get_drvdata(dev);
+ dev_set_drvdata(dev, NULL);
drm_dev_unregister(drm);
drm_kms_helper_poll_fini(drm);
drm_atomic_helper_shutdown(drm);
--
2.35.1
